Now, unless we believe that an 83 IQ is sufficient to invent number systems–do we?–something must have drastically lowered the intelligence of those white purebred Indians. What? Since we are all good Darwinians, there must have been strong selective pressures for stupidity. This suggests a very modern organization of society. Here we enter the ghostly realm of genes assumed to exist acted upon by selective pressures that can neither be measured nor shown to have existed to produce effects which cannot be correlated with the pressures that may or may not have existed.